For economic reasons, it is desirable for a seal of a piston-cylinder assembly to function for as long as possible before needing replacement. For example, a typical target is hundreds or thousands of hours of operation. During these run hours the seal wears down radially, and gaps may form between portions of the seal. The total circumferential arc length of the resulting gap(s) opens by 2*pi*the radial wear of the seal. With a self-lubricating material in which the wear rate is relatively high, the gap opens by an amount that results in unacceptable leakage flow, thus limiting the effective operating life of the seal.